Allergic disease in urban and rural populations: increasing prevalence with increasing urbanization

Associations of dietary vitamin A and C intake with asthma, allergic rhinitis, and allergic respiratory diseases

BACKGROUND/OBJECTIVES

Asthma and allergic rhinitis (AR) are closely related and considered as allergic respiratory diseases (ARD), and their prevalence has recently increased. Data on the association of dietary antioxidant vitamin intake with asthma and AR in adults are limited. The present study aimed to investigate the associations of vitamin A and C intake with asthma, AR, and all cases of both diseases in young adults who participated in a cross-sectional national survey, with the use of high-sensitivity C-reactive protein (hs-CRP) level as an effect modifier.

SUBJECTS/METHODS

This study included 6,293 male and female adults aged 20-49 years from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted between 2016 and 2018. The questionnaire-based reports on asthma and AR diagnosis were used to determine outcome variables. Further, 24-h recall data on dietary vitamin A and C, carotene, and retinol intake were acquired. Logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence interval (CI).

RESULTS

Dietary vitamin C intake was inversely associated with asthma prevalence among participants with hs-CRP levels (≥ 1 mg/L); the OR of asthma prevalence was 0.27 (95% CI, 0.08-0.84) for participants with vitamin C consumption ≥ 75 mg/day compared with those consuming < 20 mg/day. Similar association analyses limiting to non-users of dietary supplements were performed to rule out the potential effects of supplement intake on the outcomes; results showed a stronger association. However, the association between vitamin C and asthma was not significant in participants with hs-CRP levels < 1 mg/L; the OR of asthma was 1.44 (95% CI, 0.66-3.16) for participants with vitamin C consumption ≥ 75 mg/day compared with those consuming < 20 mg/day. Vitamin C intake was not associated with AR. Moreover, there was no association between vitamin A intake and neither asthma nor AR.

CONCLUSIONS

These findings suggest that higher vitamin C intake may play a potential role in reducing asthma prevalence. Nevertheless, further studies should be conducted to evaluate whether this association is causal.

Geo-climatic risk factors for chronic rhinosinusitis in southwest Iran

Chronic rhinosinusitis (CRS) is a prevalent and disabling paranasal sinus disease associated with some environmental factors. In this study, we evaluated the effect of geo-climatic factors on CRS in a region of southwest Iran. The study mapped the residency addresses of 232 patients with CRS who lived in Kohgiluyeh and Boyer-Ahmad province and had undergone sinus surgery from 2014 to 2019. The effects of Mean Annual Humidity (MAH), Mean Annual Rainfall (MAR), Mean Annual Temperature (MAT), maximum MAT (maxMAT), minimum MAT (minMAT), Mean Annual Evaporation (MAE), wind, elevation, slope, and land cover were assessed on the occurrence of CRS using Geographical Information System (GIS). Statistical analysis was performed using univariate and multivariate binary logistic regression. Patients came from 55 points including villages, towns, and cities. In univariate analysis, climatic factors including MAT (OR = 0.537), minMAT (OR = 0.764), maxMAT (OR = 0.63), MAR (OR = 0.994), and MAH (OR = 0.626) were significantly related to CRS occurrence. Elevation (OR = 0.999), slope (OR = 0.9), and urban setting (OR = 24.667) were the significant determinants among geographical factors when analyzed independently. The multivariate analysis found maxMAT (OR = 0.5), MAR (OR = 0.994), elevation (OR = 0.998), and urban (OR = 16.8) as significant factors affecting CRS occurrence. The urban setting is the most critical factor affecting CRS disease. Cold and dry areas and low attitude are the other risk factors for CRS in Kohgiluyeh and Boyer-Ahmad province, southwest Iran.

Intranasal administration of Acinetobacter lwoffii in a murine model of asthma induces IL-6-mediated protection associated with cecal microbiota changes

BACKGROUND

Early-life exposure to certain environmental bacteria including Acinetobacter lwoffii (AL) has been implicated in protection from chronic inflammatory diseases including asthma later in life. However, the underlying mechanisms at the immune-microbe interface remain largely unknown.

METHODS

The effects of repeated intranasal AL exposure on local and systemic innate immune responses were investigated in wild-type and Il6-/- , Il10-/- , and Il17-/- mice exposed to ovalbumin-induced allergic airway inflammation. Those investigations were expanded by microbiome analyses. To assess for AL-associated changes in gene expression, the picture arising from animal data was supplemented by in vitro experiments of macrophage and T-cell responses, yielding expression and epigenetic data.

RESULTS

The asthma preventive effect of AL was confirmed in the lung. Repeated intranasal AL administration triggered a proinflammatory immune response particularly characterized by elevated levels of IL-6, and consequently, IL-6 induced IL-10 production in CD4+ T-cells. Both IL-6 and IL-10, but not IL-17, were required for asthma protection. AL had a profound impact on the gene regulatory landscape of CD4+ T-cells which could be largely recapitulated by recombinant IL-6. AL administration also induced marked changes in the gastrointestinal microbiome but not in the lung microbiome. By comparing the effects on the microbiota according to mouse genotype and AL-treatment status, we have identified microbial taxa that were associated with either disease protection or activity.

CONCLUSION

These experiments provide a novel mechanism of Acinetobacter lwoffii-induced asthma protection operating through IL-6-mediated epigenetic activation of IL-10 production and with associated effects on the intestinal microbiome.

Niche-Based Microbial Community Assemblage in Urban Transit Systems and the Influence of City Characteristics

Microbiota residing on the urban transit systems (UTSs) can be shared by travelers and have niche-specific assemblage. However, it remains unclear how the assemblages are influenced by city characteristics, rendering city-specific and microbial-aware urban planning challenging. Here, we analyzed 3,359 UTS microbial samples collected from 16 cities around the world. We found the stochastic process dominated in all UTS microbiota assemblages, with the explanation rate (R2) of the neutral community model (NCM) higher than 0.7. Moreover, city characteristics predominantly drove such assemblage, largely responsible for the variation in the stochasticity ratio (50.1%). Furthermore, by utilizing an artificial intelligence model, we quantified the ability of UTS microbes in discriminating between cities and found that the ability was also strongly affected by city characteristics, especially climate and continent. From these, we found that although the NCM R2 of the New York City UTS microbiota was 0.831, the accuracy of the microbial-based city characteristic classifier was higher than 0.9. This is the first study to demonstrate the effects of city characteristics on the UTS microbiota assemblage, paving the way for city-specific and microbial-aware applications. IMPORTANCE We analyzed the urban transit system microbiota assemblage across 16 cities. The stochastic process was dominant in the urban transit system microbiota assemblage. The urban transit system microbe's ability in discriminating between cities was quantified using transfer learning based on random forest (RF) methods. Certain urban transit system microbes were strongly affected by city characteristics.

Association of helminth infestation with childhood asthma: a nested case-control study

OBJECTIVES

The association between helminthiasis and asthma remains inconclusive but can only be investigated in counties where helminthiasis is transitioning from a high to low burden. We investigated this association using data from a childhood respiratory cohort in Sri Lanka.

METHODS

A case-control study was nested within a population-based cohort of children aged 6-14 years in Sri Lanka. The stool samples of 190 children with asthma and 190 children without asthma were analyzed to assess the burden of helminth infestation. Logistic regression models were fitted to investigate the association of gastrointestinal helminth species with asthma.

RESULTS

Helminthiasis in children with and without asthma was 23.3% (n = 44) and 15.3% (n = 23), respectively. Those with asthma were more likely to have helminthiasis (odds ratio 3.7; 95% confidence interval 1.7, 7.7; P = 0.001), particularly with Trichiuris trichura (odds ratio 4.5; 95% confidence interval 1.6, 12.3; P = 0.004). Helminth eggs per gram of feces were not associated with asthma (P >0.05).

CONCLUSION

Our findings demonstrate a positive association between T. trichura infestation and asthma and point to the need to fully characterize this association to understand the likely immunological mechanism that drives it. This association highlights an important public health intervention in countries where these infestations are still prevalent, affecting 24% of the population worldwide.

Allergic rhinitis in India

India is the home of nearly 20% of the global population with 1.35 billion people. Of all non-communicable diseases, allergic diseases such as allergic rhinitis (AR) and asthma appear to have increased in India over the past decades. Approximately 22% of adolescents currently suffer from AR in India. However, owing to the lack of adequate epidemiological studies in India, particularly in rural and suburban areas, this number may misrepresent the true burden of this disease. While the risk factors for AR are mainly environmental exposures or genetic factors, several new environmental, social, and behavioural risk factors such as the presence of dumpsters near residences, movement of vehicles near homes, and exposure to artificial light at night have been found to be associated with AR. However, despite international guidelines, the diagnosis and management of AR in India are often suboptimal, for multiple reasons such as the lack of specialized training in allergy and immunology among Indian clinicians, the lack of diagnostic facilities, and the high cost of medications. This review aims at highlighting the current scenario of AR in India and how it differs from the rest of the world. It also highlights the need for developing a strategic approach to enhance the quality of care for allergic diseases by upgrading education and training for healthcare professionals, creating awareness among clinicians and patients, and involving stakeholders and policymakers in making treatments accessible and affordable to patients.

Urban Microbiomes in Narita, Chiba, Japan: Shotgun Metagenome Sequences of a Train Station

Here, we performed shotgun metagenome sequencing of swab samples collected on floors at a train station in Narita City, Chiba, Japan. The taxonomic analysis revealed that Actinobacteria and Proteobacteria were the dominant phyla. The data will contribute to insight into the microbiome community on the surfaces of urban built environments.

Understanding the development of Th2 cell-driven allergic airway disease in early life

Allergic diseases, including atopic dermatitis, allergic rhinitis, asthma, and food allergy, are caused by abnormal responses to relatively harmless foreign proteins called allergens found in pollen, fungal spores, house dust mites (HDM), animal dander, or certain foods. In particular, the activation of allergen-specific helper T cells towards a type 2 (Th2) phenotype during the first encounters with the allergen, also known as the sensitization phase, is the leading cause of the subsequent development of allergic disease. Infants and children are especially prone to developing Th2 cell responses after initial contact with allergens. But in addition, the rates of allergic sensitization and the development of allergic diseases among children are increasing in the industrialized world and have been associated with living in urban settings. Particularly for respiratory allergies, greater susceptibility to developing allergic Th2 cell responses has been shown in children living in urban environments containing low levels of microbial contaminants, principally bacterial endotoxins [lipopolysaccharide (LPS)], in the causative aeroallergens. This review highlights the current understanding of the factors that balance Th2 cell immunity to environmental allergens, with a particular focus on the determinants that program conventional dendritic cells (cDCs) toward or away from a Th2 stimulatory function. In this context, it discusses transcription factor-guided functional specialization of type-2 cDCs (cDC2s) and how the integration of signals derived from the environment drives this process. In addition, it analyzes observational and mechanistic studies supporting an essential role for innate sensing of microbial-derived products contained in aeroallergens in modulating allergic Th2 cell immune responses. Finally, this review examines whether hyporesponsiveness to microbial stimulation, particularly to LPS, is a risk factor for the induction of Th2 cell responses and allergic sensitization during infancy and early childhood and the potential factors that may affect early-age response to LPS and other environmental microbial components.

The Prevalence, Clinical Picture, and Triggers of Allergic Rhinitis in Saudi Population: A Systematic Review and Meta-Analysis

Objective

To summarize the current evidence regarding the prevalence of Allergic rhinitis (AR) and its symptoms, triggers, and impact on the quality of life of the Saudi population.

Methods

A Computerized Search in MEDLINE via PubMed, MEDLINE Core database, Scopus, and Web of Science was conducted using relevant keywords. A two-stage screening process, data extraction, and quality assessment were conducted by four independent reviewers. Comprehensive Meta-analysis was used for all statistical analyses (CMA; USA: version 3.3.070).

Results

Sixteen articles (n= 31,990 patients) were included. The overall estimated prevalence of AR was 21.2%, 95% CI (12.8-33.1%). Males had a higher prevalence of AR than females (31.7% vs 27.1%), although the difference was not significant (OR=1.24, 95% CI: 0.78-1.953; p=0.356). Children and adolescents exhibited a lower prevalence of AR than adults (13.7% vs 31.1%). Urban AR prevalence was much greater than rural (38.4% vs 13.0%). Asthma, atopic dermatitis, and eczema are all associated with AR. The most common signs and symptoms of AR were headache 33.9%, watery discharge 28.6%, sneezing 24.6%, itchy nose, runny nose 22.2%, nasal obstruction or congestion 22.0%, loss of smell 21.9%, and wheezing 17.2%. The most prevalent triggers of AR were perfume 36.8%, dust 27.3%, air conditioning 23.4%, weather or temperature changes 17.8%, air pollution 14.5%, drugs or chemicals 13.8%, tobacco 10.8%, atopy 10.3%, and insects 10.2%.

Conclusion

The overall prevalence of AR in Saudi Arabia is 21.2%. The prevalence of AR was comparable in both males and females. However, it was higher in adults than in children and adolescents, and in urban areas than rural areas. Asthma, atopic dermatitis, and eczema co-occurrence with AR are common. AR has a negative impact on the quality of life of the patients in the form of interference with daily activities, sleep problems, difficulty of breath, and school absenteeism.

Untargeted Fecal Metabolomic Analyses across an Industrialization Gradient Reveal Shared Metabolites and Impact of Industrialization on Fecal Microbiome-Metabolome Interactions

The metabolome is a central determinant of human phenotypes and includes the plethora of small molecules produced by host and microbiome or taken up from exogenous sources. However, studies of the metabolome have so far focused predominantly on urban, industrialized populations. Through an untargeted metabolomic analysis of 90 fecal samples from human individuals from Africa and the Americas-the birthplace and the last continental expansion of our species, respectively-we characterized a shared human fecal metabolome. The majority of detected metabolite features were ubiquitous across populations, despite any geographic, dietary, or behavioral differences. Such shared metabolite features included hyocholic acid and cholesterol. However, any characterization of the shared human fecal metabolome is insufficient without exploring the influence of industrialization. Here, we show chemical differences along an industrialization gradient, where the degree of industrialization correlates with metabolomic changes. We identified differential metabolite features such as amino acid-conjugated bile acids and urobilin as major metabolic correlates of these behavioral shifts. Additionally, coanalyses with over 5,000 publicly available human fecal samples and cooccurrence probability analyses with the gut microbiome highlight connections between the human fecal metabolome and gut microbiome. Our results indicate that industrialization significantly influences the human fecal metabolome, but diverse human lifestyles and behavior still maintain a shared human fecal metabolome. This study represents the first characterization of the shared human fecal metabolome through untargeted analyses of populations along an industrialization gradient. IMPORTANCE As the world becomes increasingly industrialized, understanding the biological consequences of these lifestyle shifts and what it means for past, present, and future human health is critical. Indeed, industrialization is associated with rises in allergic and autoimmune health conditions and reduced microbial diversity. Exploring these health effects on a chemical level requires consideration of human lifestyle diversity, but understanding the significance of any differences also requires knowledge of what molecular components are shared between human groups. Our study reveals the key chemistry of the human gut as defined by varied industrialization-based differences and ubiquitous shared features. Ultimately, these novel findings extend our knowledge of human molecular biology, especially as it is influenced by lifestyle and behavior, and provide steps toward understanding how human biology has changed over our species' history.

Grassland allergenicity increases with urbanisation and plant invasions

Pollen allergies have been on the rise in cities, where anthropogenic disturbances, warmer climate and introduced species are shaping novel urban ecosystems. Yet, the allergenic potential of these urban ecosystems, in particular spontaneous vegetation outside parks and gardens, remains poorly known. We quantified the allergenic properties of 56 dry grasslands along a double gradient of urbanisation and plant invasion in Berlin (Germany). 30% of grassland species were classified as allergenic, most of them being natives. Urbanisation was associated with an increase in abundance and diversity of pollen allergens, mainly driven by an increase in allergenic non-native plants. While not inherently more allergenic than native plants, the pool of non-natives contributed a larger biochemical diversity of allergens and flowered later than natives, creating a broader potential spectrum of allergy. Managing novel risks to urban public health will involve not only targeted action on allergenic non-natives, but also policies at the habitat scale favouring plant community assembly of a diverse, low-allergenicity vegetation. Similar approaches could be easily replicated in other cities to provide a broad quantification and mapping of urban allergy risks and drivers.

Childhood allergic diseases across geographical regions of Kandy and Anuradhapura districts of Sri Lanka; where do the rates stand among other regions: experience from Global asthma network Phase 1 study

Background

Asthma, allergic rhinitis and eczema have been identified as the most prevalent childhood allergic diseases. However, the prevalence of these allergic diseases can vary in different regions within a country and in the world.

Methods

The objective of the study was to estimate the prevalence of asthma, allergic rhinitis and eczema in schoolchildren in the Kandy and Anuradhapura districts of Sri Lanka. This was a multicentre cross sectional study carried out among children of age 6–7 years and 13–14 years attending state schools fulfilling the entry criteria of the Global Asthma Network Phase 1 study methodology.

Results

A total of 3673 children of 6–7 years and 4658 children of 13–14 years were recruited. The prevalence of current asthma, allergic rhinitis and eczema were 12% (CI 10.44–13.75), 15.7% (CI 13.94–17.64) and 9.7% (CI 8.30–11.31) among 6–7 years age group and 15.3% (CI 13.66–17.09), 30.5% (CI 28.86–32.74) and 7.3% (CI 6.15–8.65) respectively among the 13–14 age group in Kandy district. The reported prevalence rates of the disease conditions were 9.9% (CI 8.72–11.22), 10.1% (CI 8.90–11.44) and 5.9% (CI 4.98–6.98) among 6–7 years age group and 14.9% (CI 13.67–16.22), 22.5% (CI 21.04–24.03) and 1.8% (CI 1.38–2.34) in the 13–14 years age group in Anuradhapura district. When comparing these prevalence rates, there is relatively a higher prevalence of childhood allergic diseases in Kandy district. This difference is statistically significant in all three allergic disease conditions (P < 0.001).

Conclusion

Prevalence of allergic diseases in Anuradhapura is closer to reported data in the previous studies. There is relatively higher prevalence of childhood allergic diseases among children in Kandy district.

The impact of urbanization and wealth on house dust mite sensitization in children from north-central Nigeria

The impact of socio-economic status on the risk of allergy in African children is not clear.

This was a cross sectional study including children aged 6–14 years from urban and rural settings in north-central Nigeria. Participants underwent skin prick tests to house dust mite (HDM) and an interview investigating socio-economic status through the Family Affluence Scale (FAS) based on a score of 0–6.

A total of 346 children were enrolled (52.8% boys; mean age ± SD 9.6 ± 2.0 years), including 142 (41% of total) rural and 204 (59% of total) urban pupils. Prevalence of HDM sensitivity was 2.8% (4/142) in the rural setting and 15.6% (32/204) in the urban setting (P < 0.001). Among urban children, frequency of HDM sensitization was 8.6% (7/81) in the lowest socio-economic group (FAS 0–1), 13.1% (8/61) in the intermediate one (FAS 2–3) and 27.4% (17/62) in the highest one (FAS ≥ 4).

Urbanization and increasing wealth are associated with a higher frequency of sensitization to HDM in Nigerian children.

Place of residence, gender, month of birth and age influence on the concentration of specific IgE antibodies in serum. The Epidemiology of Allergic Diseases in Poland (ECAP survey): part three

Introduction

Specific immunoglobulins E (sIgE) are important parameters to estimate the severity of allergic diseases.

Aim

To determine the influence of gender, age and place of residence on the concentration of specific IgE antibodies in serum.

Material and methods

The concentration of sIgE antibodies against allergens of Dermatophagoides pteronyssinus, cat dander, timothy grass, Alternaria alternata were determined in serum of 4077 respondents randomly selected from 8 regions (ECAP study). The positive results of sIgE (≥ 0.35 IU/ml) were correlated with answers to ECAP questionnaires.

Results

IgE antibodies are less frequently detected in respondents living in the country (p < 0.05 to p < 0.005); and they are less frequently detected in respondents living in cities of hardly industrialised regions than in respondents living in cities of industrialised regions (D. pteronyssinus p < 0.05, cat dander p < 0.01). IgE antibodies are more frequently detected in men (p < 0.005 to p < 0.001). IgE antibodies are more frequently detected in respondents born in May-July (timothy grass p < 0.005, Alternaria alternata p < 0.005) and less frequently detected in respondents born in August-October (timothy grass p < 0.005, Alternaria alternata p < 0.05).

Conclusions

Characteristics of the urban environment, non-specific factors and gender affect the concentration of specific IgE antibodies in serum. Influence of seasonal allergens within the first months of life and/or in the course of the foetal period alters the production of specific IgE antibodies.

Inborn Errors of Immunity Associated With Type 2 Inflammation in the USIDNET Registry

Background

Monogenic conditions that disrupt proper development and/or function of the immune system are termed inborn errors of immunity (IEIs), also known as primary immunodeficiencies. Patients with IEIs often suffer from other manifestations in addition to infection, and allergic inflammation is an increasingly recognized feature of these conditions.

Methods

We performed a retrospective analysis of IEIs presenting with allergic inflammation as reported in the USIDNET registry. Our inclusion criteria comprised of patients with a reported monogenic cause for IEI where reported lab eosinophil and/or IgE values were available for the patient prior to them receiving potentially curative therapy. Patients were excluded if we were unable to determine the defective gene underlying their IEI. Patients were classified as having eosinophilia or elevated IgE when their record included at least 1 eosinophil count or IgE value that was greater than the age stratified upper limit of normal. We compared the proportion of patients with eosinophilia or elevated IgE with the proportion of samples in a reference population that fall above the upper limit of normal (2.5%).

Results

The query submitted to the USIDNET registry identified 1409 patients meeting inclusion criteria with a monogenic cause for their IEI diagnosis, of which 975 had eosinophil counts and 645 had IgE levels obtained prior to transplantation or gene therapy that were available for analysis. Overall, 18.8% (183/975) of the patients evaluated from the USIDNET registry had eosinophilia and 20.9% (135/645) had an elevated IgE. IEIs caused by defects in 32 genes were found to be significantly associated with eosinophilia and/or an elevated IgE level, spanning 7 of the 10 IEI categories according to the International Union of Immunological Societies classification.

Conclusion

Type 2 inflammation manifesting as eosinophilia or elevated IgE is found in a broad range of IEIs in the USIDNET registry. Our findings suggest that allergic immune dysregulation may be more widespread in IEIs than previously reported.

Sensitisation to Imbrasia belina (mopane worm) and other local allergens in rural Gwanda district of Zimbabwe

Background

The prevalence of allergic diseases is increasing in Zimbabwe and the data relate to local as well as exotic allergen sources. As entomophagy, the practice of eating insects, is a recognised source of local allergens, we sought to measure the prevalence of and risk factors for sensitisation to Imbrasia belina (mopane worm), a popular edible insect. This was investigated alongside other locally relevant allergens in a rural community in Gwanda district, south of Zimbabwe.

Methods

A cross sectional study was conducted among 496 adults and children aged 10 years and above in Gwanda district, a mopane worm harvesting area in Zimbabwe. Data on individual characteristics and mopane worm exposure factors were collected using questionnaires. Sensitivity to allergens was assessed by performing skin prick tests at a local clinic using 10 different commercial allergen extracts (Stallergenes, France) and in-house extracts of mopane worm (Imbrasia belina) and mopane leaves (Colophospermum mopane). Data were analysed using Stata version 13 software.

Results

The prevalence of sensitisation to at least one allergen was 31.17% (n = 144). The prevalence of atopy was higher in adults (33.33%) than in children (23.53%) (p = 0.059). The commonest inhalant allergen sources were mopane worm (14.29%), Tyrophagus putrescentiae (14.29%), mopane leaves (13.42%), Alternaria alternata (6.49%) and Dermatophagoides pteronyssinus (6.49%). Polysensitisation was demonstrated in the study population and of the 108 participants (75%) who were sensitised to two or more allergens, 66 (61%) were women. Sensitisation to mopane worm and mopane leaves often clustered with Tyrophagus putrescentiae amongst adults. Adjusted logistic regression analyses between mopane worm sensitisation and self-reported exposure variables showed that sensitisation was more likely amongst mopane worm harvesters (OR = 1.92, 95%CI = 0.77–4.79), those who cooked or roasted mopane worms during harvesting (OR = 2.69, 95%CI = 0.78–9.31) and harvesting without personal protective equipment (PPE) (OR = 2.12, 95%CI = 0.83–5.44) compared to non-harvesters.

Conclusion

Atopic sensitization was common in this mopane worm harvesting community in Gwanda district of Zimbabwe. There was frequent co-sensitisation of mopane worm and mopane leaves with Tyrophagus putrescentiae in children and adults. It is important to determine the clinical relevance of our findings, particularly relating to mopane worm sensitisation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00668-0.

A microbiome study reveals the potential relationship between the bacterial diversity of a gymnastics hall and human health

Currently, investigations on the microbiota of sports centers and related facilities have been carried out in some countries, which showed that Microsporum gypseum, Trichophyton mentagrophytes and T. tonsurans are important dermatoprotofungi. In China, some research on athletes and sports equipment between the fungal community and public health has made some interesting achievements. However, the bacterial group among them has not been reported. Therefore, The aim of this study was to uncover (I) gymnastic equipment is there potential pathogenic factors and (ii) is there any difference in the biomarker of bacterial in different types of gymnastic room? The samples were collected from the gymnastics halls of one university in western China and main sports equipment, including gymnastics carpets, moving barres, hoops and balls, as well as wall bars, parallel bars and horizontal bars. The 16S rDNA of all the samples was sequenced, and the analyses were performed using FaproTax, Bug base function prediction and Line Discriminant Analysis (LDA) Effect Size. A 16S rDNA sequence analysis revealed abundant bacterial species biodiversity on gymnasts and apparatuses from two gymnastics halls at a university in western China. An analysis using the FaproTax and Bugbase functional prediction platforms showed that there were some opportunistic pathogens on the athletes and equipment from the Rhythmic Gymnastics (RG) and Artistic Gymnastics (AG) halls, such as Staphylococcus and Corynebacteiaceae. Infectious agents associated with cancer induction and development, such as Ruminococcaceae, Veillonellaceae and Moraxellaceae, as well as microbial toxin producers with a potential impact on human health, were also detected. According to a line discriminant analysis (LDA effect size), the bacterial biomarker groups of the two gymnasiums were different at the phylum-genus level: for RG, Erysipelatoclostridium, Lachnospiraceae and Bacteroidales, while for AG, Rhizobiales. Based on the results of the investigation, we suggest that more comprehensive consideration should be given to indoor microbial biodiversity and related public health problems in school gymnasiums.

Barriers and determinants of asthma control in children and adolescents in Africa: a systematic review

OBJECTIVE

To identify reasons for poor asthma control in African children and adolescents.

DESIGN

Systematic review DATA SOURCES: PubMed, Scopus, CINHAL, PsycINFO, MEDLINE and Web of Science databases were systematically searched up to 31 May 2020. Hand searching was done on Sabinet, African Journal online and Google Scholar.

ELIGIBILITY CRITERIA

Studies identifying barriers to asthma control, where asthma control was assessed by the validated Asthma Control Test/Child Asthma Control Test and/or Asthma Control Questionnaire were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently selected studies for inclusion with disagreements resolved by a research team discussion, including a third reviewer. Data were extracted using the Cochrane Effective Practice and Organization of Care data collection form. The quality of the included studies was assessed using the modified Newcastle-Ottawa quality assessment scale. Identified barriers were reported in a thematic narrative synthesis.

PRIMARY OUTCOMES

Poorly controlled asthma and associated factors.

RESULTS

From 914 records, three studies conducted between 2014 and 2019 in Nigeria, Uganda and South Africa met the inclusion criteria. A total of 883 children aged 4-19 years were analysed. Older age, concurrent allergy and city-dwelling significantly impacted asthma control. Few children with asthma symptoms in the community had ever used inhaled corticosteroids (6.7%) and identified reasons included lack of asthma diagnosis (38.8%) and no prescribed treatment (47.6%).

CONCLUSION

Asthma control in African children is impacted by age, allergy, urbanisation and lack of access to asthma diagnosis and treatment. More studies focusing on identifying barriers to asthma control in Africa are needed.

PROSPERO

Registration no: CRD42020196755).

Associations between phthalic acid esters in household dust and childhood asthma in Shanghai, China

Phthalic acid esters (PAEs) have a negative impact on human health and are widely distributed in China. As part of the China, Children, Home, Health (CCHH) study, we investigated the associations between childhood asthmatic symptoms and PAEs in settled house dust in Shanghai, China. We found that di-2-ethylhexyl phthalate (DEHP), dibutyl phthalate (DBP), and diisobutyl phthalate (DiBP) were abundant in the indoor environment. A total of 27 % of children suffered from diagnosed asthma. The Mann-Whitney U test and multiple logistic regression were used to obtain the associations between PAEs and childhood asthmatic symptoms. Stratification analysis was performed to reveal the influence of gender on the associations between PAE exposure and target symptoms. Compared with low concentrations of PAEs, high concentrations of high molecular weight PAEs (HMW-PAEs) were significantly associated with childhood diagnosed asthma (adjusted odds ratios (AORs) > 1, P < 0.05). Moreover, significantly negative associations were found between high concentrations of DiBP and current cough (AORs<1, P < 0.05). All significantly positive associations were observed among girls, and most of the associations of dimethyl phthalate (DMP) and diethyl phthalate (DEP) exposure with the studied symptoms among girls were higher than those among boys. Exposure to PAEs may be a risk factor for asthmatic symptoms in children, especially in girls.

Asthma, Allergic Rhinitis, and Atopic Dermatitis Incidence in Korean Adolescents before and after COVID-19

With changes in personal habits (masks and handwashing) during the COVID-19 outbreak, the study analyzed the reporting of physician-diagnosed cases (incidence) of allergic diseases (asthma, allergic rhinitis, and atopic dermatitis) using the data for years 2019 and 2020 from the Korean adolescent risk behavior web-based survey (KYRBWS-15 and 16). Altogether, 92,659 adolescents (48,443 in 2019 and 44,216 in 2020) were enrolled. The crude and adjusted odd ratios (ORs) were calculated for each disease in 2020 compared to that in 2019 using multiple logistic regression. Subgroup analyses were performed according to sex and economic status. The incidence of asthma decreased from 1.5% in 2019 to 1.0% 2020 (p < 0.001). The incidence of allergic rhinitis in 2019 and 2020 was 19.5% and 16.3%, respectively (p < 0.001). Compared with 2019, the adjusted OR (aOR) in 2020 was 0.68 (95% CI = 0.66–0.77, p value < 0.001) for asthma and 0.82 (95% CI = 0.78–0.85, p < 0.001) for allergic rhinitis. In contrast, there was no statistically significant difference between the incidence of atopic dermatitis in 2019 and that in 2020 (6.4%, vs. 6.4%, p > 0.05, respectively). Subgroup analyses results were consistent. In conclusion, there was decrease in the incidence of asthma and allergic rhinitis but not in that of atopic dermatitis from 2019 to 2020.

Aspergillus-Associated Endophenotypes in Bronchiectasis

Bronchiectasis is a chronic condition of global relevance resulting in permanent and irreversible structural airway damage. Bacterial infection in bronchiectasis is well studied; however, recent molecular studies identify fungi as important pathogens, either independently or in association with bacteria. Aspergillus species are established fungal pathogens in cystic fibrosis and their role is now increasingly being recognized in noncystic fibrosis bronchiectasis. While the healthy airway is constantly exposed to ubiquitously present Aspergillus conidia in the environment, anatomically damaged airways appear more prone to colonization and subsequent infection by this fungal group. Aspergilli possess diverse immunopathological mechanistic capabilities and when coupled with innate immune defects in a susceptible host, such as that observed in bronchiectasis, it may promote a range of clinical manifestations including sensitization, allergic bronchopulmonary aspergillosis, Aspergillus bronchitis, and/or invasive aspergillosis. How such clinical states influence "endophenotypes" in bronchiectasis is therefore of importance, as each Aspergillus-associated disease state has overlapping features with bronchiectasis itself, and can evolve, depending on underlying host immunity from one type into another. Concurrent Aspergillus infection complicates the clinical course and exacerbations in bronchiectasis and therefore dedicated research to better understand the Aspergillus-host interaction in the bronchiectasis airway is now warranted.

A global metagenomic map of urban microbiomes and antimicrobial resistance

We present a global atlas of 4,728 metagenomic samples from mass-transit systems in 60 cities over 3 years, representing the first systematic, worldwide catalog of the urban microbial ecosystem. This atlas provides an annotated, geospatial profile of microbial strains, functional characteristics, antimicrobial resistance (AMR) markers, and genetic elements, including 10,928 viruses, 1,302 bacteria, 2 archaea, and 838,532 CRISPR arrays not found in reference databases. We identified 4,246 known species of urban microorganisms and a consistent set of 31 species found in 97% of samples that were distinct from human commensal organisms. Profiles of AMR genes varied widely in type and density across cities. Cities showed distinct microbial taxonomic signatures that were driven by climate and geographic differences. These results constitute a high-resolution global metagenomic atlas that enables discovery of organisms and genes, highlights potential public health and forensic applications, and provides a culture-independent view of AMR burden in cities.

Indoor bacterial, fungal and viral species and functional genes in urban and rural schools in Shanxi Province, China-association with asthma, rhinitis and rhinoconjunctivitis in high school students

BACKGROUND

Studies in developed countries have reported that the prevalence of asthma and rhinitis is higher in urban areas than in rural areas, and this phenomenon is associated with urbanization and changing indoor microbiome exposure. Developing countries such as China have experienced rapid urbanization in past years, but no study has investigated microbiome exposure and urban-rural health effects in these countries.

METHODS

Nine high schools from urban and rural areas were randomly selected in Shanxi Province, China, and classroom vacuum dust was collected for shotgun metagenomic sequencing. A self-administered questionnaire was collected from 1332 students for personal information and health data. Three-level logistic regression was performed between microbial richness/abundance/functional pathways and the occurrence of asthma and rhinitis symptoms.

RESULTS

Consistent with developed countries, the prevalence of wheeze and rhinitis was higher in urban areas than in rural areas (p < 0.05). Metagenomic profiling revealed 8302 bacterial, 395 archaeal, 744 fungal, 524 protist and 1103 viral species in classroom dust. Actinobacteria (mean relative abundance 49.7%), Gammaproteobacteria (18.4%) and Alphaproteobacteria (10.0%) were the most abundant bacterial classes. The overall microbiome composition was significantly different between urban and rural schools (p = 0.001, Adonis). Species from Betaproteobactera, Gammaproteobacteria and Bacilli were enriched in urban schools, and species from Actinobacteria and Cyanobacteria were enriched in rural schools. Potential pathogens were present in higher abundance in urban schools than in rural schools (p < 0.05). Pseudoalteromonas, Neospora caninum and Microbacterium foliorum were positively associated with the occurrence of wheeze, rhinitis and rhinoconjunctivitis, and Brachybacterium was protectively (negatively) associated with rhinitis (p < 0.01). The abundance of human endocrine and metabolic disease pathways was positively associated with rhinitis (p = 0.008), and butyrate and propionate metabolic genes and pathways were significantly enriched in rural schools (p < 0.005), in line with previous findings that these short-chain fatty acids protect against inflammatory diseases in the human gut.

CONCLUSIONS

We conducted the first indoor microbiome survey in urban/rural environments with shotgun metagenomics, and the results revealed high-resolution microbial taxonomic and functional profiling and potential health effects. Video abstract.

Strong variations in urban allergenicity riskscapes due to poor knowledge of tree pollen allergenic potential

Exposure to allergenic tree pollen is an increasing environmental health issue in urban areas. However, reliable, well-documented, peer-reviewed data on the allergenicity of pollen from common tree species in urban environments are lacking. Using the concept of 'riskscape', we present and discuss evidence on how different tree pollen allergenicity datasets shape the risk for pollen-allergy sufferers in five cities with different urban forests and population densities: Barcelona, Montreal, New York City, Paris, and Vancouver. We also evaluate how tree diversity can modify the allergenic risk of urban forests. We show that estimates of pollen exposure risk range from 1 to 74% for trees considered to be highly allergenic in the same city. This variation results from differences in the pollen allergenicity datasets, which become more pronounced when a city's canopy is dominated by only a few species and genera. In an increasingly urbanized world, diverse urban forests offer a potentially safer strategy aimed at diluting sources of allergenic pollen until better allergenicity data is developed. Our findings highlight an urgent need for a science-based approach to guide public health and urban forest planning.

Bioaerosols in urban environments: Trends and interactions with pollutants and meteorological variables based on quasi-climatological series

Pollen grains emitted by urban vegetation are the main primary biological airborne particles (PBAPs) which alter the biological quality of urban air and have a significant impact on human health. This work analyses the interactions which exist between pollen-type PBAPs, meteorological variables, and air pollutants in the urban atmosphere so that the complex relationships and trends in future scenarios of changing environmental conditions can be assessed. For this study, the 1992-2018 pollen data series from the city of Granada (southeast Spain) was used, in which the dynamics of the total pollen as well as the 8 main pollen types (Cupressaceae, Olea, Pinus, Platanus, Poaceae, Populus, Quercus and Urticaceae) were analysed. The trend analysis showed that all except Urticaceae trended upward throughout the series. Spearman's correlations with meteorological variables showed that, in general, the most influential variables on the pollen concentrations were the daily maximum temperature, relative humidity, water vapor pressure, global radiation, and insolation, with different effects on different pollen types. Parallel analysis by neural networks (ANN) confirmed these variables as the predominant ones, especially global radiation. The correlation with atmospheric pollutants revealed that ozone was the pollutant with the highest influence, although some pollen types also showed correlation with NO₂, SO₂, CO and PM₁₀. The Generalized Linear Models (GLM) between pollen and pollutants also indicated O₃ as the most prominent variable. These results highlight the active role that pollen-type PBAPs have on urban air quality by establishing their interactions with meteorological variables and pollutants, thereby providing information on the behaviour of pollen emissions under changing environmental conditions.

Atopy and Lifestyle Survey of Allergic Patients From Urban Environment in Romania: Preliminary Data From an Interactive Qualifying Project

Introduction

Respiratory allergies represent an important public health problem, with increasing prevalence and severity in Europe during the last decades. The rise of pollen allergies is an issue that continues to negatively impact people’s daily lives across the globe and has become more important in the light of global warming and increasing air pollution. The aim of our paper is to evaluate the prevalence of declared atopy and the influence of lifestyle on allergic diseases, particularly on pollen allergies, in the urban environment from Romania.

Methods

The study is based on the cooperation Interactive Qualifying Project (IQP) called “Pollen Allergies in Romania: Optimizing Data Analysis in Raising Awareness”, agreed and carried on between a group of North-American students and teachers from Worcester Polytechnic Institute and a hospital-based allergy team from Carol Davila University of Medicine and Pharmacy and Colentina Clinical Hospital from Bucharest. The project aimed to evaluate the prevalence of atopy and lifestyle practices of allergic patients and to develop a data analysis tool to determine correlations between pollen counts and other environmental factors in the city of Bucharest.

Results

The lifestyle survey revealed that about one-third of allergic patients declared history of atopy. Some of the declared lifestyle practices can be considered environmental risk factors for allergies. This IQP can be considered a model of international, interdisciplinary and intercultural collaboration.

Conclusion

We concluded that Romania is facing an increasing pollen allergies trend and some actual lifestyle aspects can significantly influence the risk of pollen allergies in the big city environment.

Pediatric Asthma: Prevalence and Socio-Cultural Factors Affecting Asthma Management in a Rural Area of Northern Karnataka

CONTEXT

Asthma prevalence and severity is increasing among Indian children. There is the paucity of data on pediatric asthma in rural India and treatment received by asthmatics is not up-to-standard treatment guidelines.

AIM

The aim is to estimate asthma prevalence and factors influencing access to standard asthmatic care among 5-15 years aged children.

SETTINGS AND DESIGN

Cross-sectional study conducted in rural north-Karnataka for 1 year.

SUBJECTS AND METHODS

The International Study of Asthma and Allergies in Childhood questionnaire was administered to participants followed by clinical examination. A child was considered as asthmatic if there was affirmative response to: (a) History of wheeze in the past 12 months, (b) Physician diagnosed/ever asthma, (c) history of taking inhaled/oral bronchodilators.

STATISTICAL ANALYSIS

All characteristics were summarized descriptively.

RESULTS

Prevalence of Current-wheeze, Ever-asthma, and wheeze on exertion were 4%, 2%, and 3.7%, respectively. About 63.9% of asthmatics had severe-asthma and 44.4% reported severe attack of wheezing limiting speech. About 89% of current-wheezers used only oral medications for wheeze/asthma, 50% did not take medicines as per doctors' advice. None availed regular follow-up. Financial constraints and ignorance were major reasons cited.

CONCLUSIONS

Illiteracy, poverty, lack of proper guidelines, and non-availability of inhalational medications have affected treatment adherence resulting in severe asthma.

Tree Allergen Pollen-Related Content as Pollution Source in the City of Ourense (NW Spain)

Allergies became a major public health problem, identified as an important global pandemic with a considerable impact on the worldwide economy. In addition, a higher prevalence of pollen Type I sensitization cases in urban environments in comparison with the rural territories was detected. Our survey sought to assess the main biological pollution episodes caused by the aeroallergens of the major allergenic tree species in urban environments. A Hirst-type volumetric device was used for pollen sampling and a Burkard Cyclone sampler for the detection of tree atmospheric allergens over two years. The main allergens of Alnus, Fraxinus, Betula, Platanus and Olea, were detected in the atmosphere. Three peaks of important pollen concentrations were recorded throughout the year. The developed regression equations between pollen counts and allergen proteins registered great R2 values. The number of days with probability of allergenic symptoms was higher when the pollen and allergen data were assessed altogether. Fraxinus allergens in the atmosphere were detected using Ole e 1 antibodies and the Aln g 1 allergens with Bet v 1 antibodies, demonstrating the cross-reaction processes between the principal allergenic proteins of the Oleaceae and Betulaceae families. Long Distance Transport processes (LDT) showed that pollen from Betula populations located in mountainous areas increased the secondary peaks of pollen and allergen concentrations, and air masses from extensive olive orchards of North-Eastern Portugal triggered the highest concentrations in the atmosphere of Olea pollen and Ole e 1 allergens.

Neighbourhood wealth, not urbanicity, predicts prosociality towards strangers

Urbanization is perhaps the most significant and rapid cause of demographic change in human societies, with more than half the world's population now living in cities. Urban lifestyles have been associated with increased risk for mental disorders, greater stress responses, and lower trust. However, it is not known whether a general tendency towards prosocial behaviour varies across the urban-rural gradient, or whether other factors such as neighbourhood wealth might be more predictive of variation in prosocial behaviour. Here, we present findings from three real-world experiments conducted in 37 different neighbourhoods, in 12 cities and 12 towns and villages across the UK. We measured whether people: (i) posted a lost letter; (ii) returned a dropped item; and (iii) stopped to let someone cross the road in each neighbourhood. We expected to find that people were less willing to help a stranger in more urban locations, with increased diffusion of responsibility and perceived anonymity in cities being measured as variables that might drive this effect. Our data did not support this hypothesis. There was no effect of either urbanicity or population density on people's willingness to help a stranger. Instead, the neighbourhood level of deprivation explained most of the variance in helping behaviour with help being offered less frequently in more deprived neighbourhoods. These findings highlight the importance of socio-economic factors, rather than urbanicity per se, in shaping variation in prosocial behaviour in humans.

Helminth Induced Immunoregulation and Novel Therapeutic Avenue of Allergy

Allergic diseases are increasing at an alarming rate worldwide, particularly in developed countries. In contrast, there is a decrease in the prevalence of helminthic infections and other neglected diseases. The hygiene hypothesis elaborates parasitic infection, and allergy-associated diseases have an inverse relationship. Acute helminthic infection and allergic reaction stimulate Type 2 helper cells (Th2) immune response with up-regulation of cytokines IL-4-, IL-5-, and IL-13-mediated IgE and mast cell production, as well as eosinophilia. However, people who chronically suffer from helminthic infections are demarcated through polarized Th2 resulting in alternative macrophage activation and T regulatory response. This regulatory system reduces allergy incidence in individuals that are chronically diseased through helminth. As a result, the excretory-secretory (ES) substance derived from parasites and extracellular vesicular components can be used as a novel therapeutic modality of allergy. Therefore, the aim of this review meticulously explored the link between helminth infection and allergy, and utilization of the helminth secretome for therapeutic immunomodulation.

Understanding vernal keratoconjunctivitis in children

Background: Vernal keratoconjunctivitis (VKC) is a public health problem that mostly affects children in warm subtropical climates. Unfortunately, the causative factors of the disease are not clearly defined, thus posing a serious management challenge to healthcare providers. It is therefore argued that understanding the pathogenesis of the disease and how various inflammatory cells affect the conjunctiva and the cornea may assist in the management of the disease.Aim: As visual impairment and avoidable blindness are indicated, it is advisable for optometrists to understand the clinical presentation of this chronic condition in order to initiate appropriate interventions and/or immediate referrals where necessary.Methods: A thorough literature search was conducted on peer-reviewed publications on VKC and children. All material obtained were then studied and the information extracted was used to document relevant information required for understanding VKC amongst children.Results: The results in the studied material revealed that VKC was prevalent amongst children aged 2 to 18 years, affecting mostly male children of African and Indian origins. Different strategies of management of the disease have been proposed, including but not limited to explaining to parents the nature of the disease, environmental strategies and preventive measures as well as possible surgical intervention.Conclusion: In view of the nature of this disease, healthcare providers should therefore seek to understand the history of the patient better when such patients present for their first consultation in order to develop a comprehensive management approach.

Environmental fungal sensitisation associates with poorer clinical outcomes in COPD

Introduction

Allergic sensitisation to fungi such as Aspergillus are associated to poor clinical outcomes in asthma, bronchiectasis and cystic fibrosis; however, clinical relevance in COPD remains unclear.

Methods

Patients with stable COPD (n=446) and nondiseased controls (n=51) were prospectively recruited across three countries (Singapore, Malaysia and Hong Kong) and screened against a comprehensive allergen panel including house dust mites, pollens, cockroach and fungi. For the first time, using a metagenomics approach, we assessed outdoor and indoor environmental allergen exposure in COPD. We identified key fungi in outdoor air and developed specific-IgE assays against the top culturable fungi, linking sensitisation responses to COPD outcomes. Indoor air and surface allergens were prospectively evaluated by metagenomics in the homes of 11 COPD patients and linked to clinical outcome.

Results

High frequencies of sensitisation to a broad range of allergens occur in COPD. Fungal sensitisation associates with frequent exacerbations, and unsupervised clustering reveals a “highly sensitised fungal predominant” subgroup demonstrating significant symptomatology, frequent exacerbations and poor lung function. Outdoor and indoor environments serve as important reservoirs of fungal allergen exposure in COPD and promote a sensitisation response to outdoor air fungi. Indoor (home) environments with high fungal allergens associate with greater COPD symptoms and poorer lung function, illustrating the importance of environmental exposures on clinical outcomes in COPD.

Conclusion

Fungal sensitisation is prevalent in COPD and associates with frequent exacerbations representing a potential treatable trait. Outdoor and indoor (home) environments represent a key source of fungal allergen exposure, amenable to intervention, in “sensitised” COPD.

Fungal sensitisation associates with frequent exacerbations in COPD, and represents a treatable trait. Outdoor and indoor environments represent a key source of fungal allergen exposure, amenable to intervention, in “sensitised” COPD patients.https://bit.ly/2Vw3kHi

Impact of air pollution on symptom severity during the birch, grass and ragweed pollen period in Vienna, Austria: Importance of O3 in 2010-2018

Air pollution is a threat to the general population, especially to pollen allergy sufferers in urban environments. Different air quality parameters have hitherto been examined which add to the burden of pollen allergy sufferers. Parameters such as NO₂, SO₂, PM₁₀, PM_2.5, and O₃ are supposed to have additional impact, not only on health in general (increase in asthma, allergy sensitization frequency), but also on pollen grains (increase of allergenicity). However, it remains unknown if those air quality parameters increase symptom severity during the pollen season. We selected the birch, grass, and ragweed pollen seasons as different time periods throughout the year and analyzed the relationship of symptom data to pollen, air quality, and meteorological data (temperature, relative humidity) for the metropolis of Vienna (Austria). A linear regression model was computed based on different symptom data, and both pollen and air quality data were tested simultaneously. Ozone was positively and significantly associated with symptom scores in all three seasons, whereas this was only rarely the case with other pollutants. Therefore, only ozone was selected for further analysis in a model including meteorological parameters. In this model, effect estimates of ozone were attenuated but remained significant for the grass pollen season. The lack of significance in the other seasons may be attributed to the less numerous symptom data entries and the shorter duration of the pollen seasons for birch and ragweed. All other air quality parameters usually showed lower concentrations during the pollen seasons and displayed little variation. This might explain the lack of a clear signal. Our results suggest that today's allergic population is already affected by air quality (rising O₃ levels). Air quality should be considered as well in pollen information and pollen allergy studies in general because of its increasing importance in the light of global warming.

Age-period-cohort analysis of asthma, allergic rhinitis, and atopic dermatitis prevalence in Japan

This study aims to analyze the trends in the Japanese prevalence of asthma, allergic rhinitis, and atopic dermatitis by using age–period–cohort (APC) analysis. Data regarding the prevalence of diseases from 1999 to 2017 were collected from Patient Survey in Japan. The data were divided according to age groups ranging from 0–4 years old up to 65–69 years old in 5-year increments. A cohort was defined for each age group of each year with a one-year shift, and cohorts born from 1930–1934 up to 2013–2017 were examined. We used Bayesian APC analysis to decompose the changes in prevalence into age, period, and cohort effects. Results show that the period effect for asthma began to increase in 2008, and those of allergic rhinitis and atopic dermatitis began to increase in 1999. The cohort effects for asthma and atopic dermatitis increased rapidly in cohorts born from approximately 1950 to 1980 and then decreased thereafter. Furthermore, the cohort effect for allergic rhinitis increased from cohorts born in approximately the late 1970s for men and in 1990 for women. The time points with increasing cohort effects for asthma and atopic dermatitis are consistent with the history of air pollution accompanied by rapid economic growth in Japan. The onset of the increased cohort effect for allergic rhinitis was also relatively consistent with the time point at which the mass scattering of pollen began.

Environmental and Endogenous Acids Can Trigger Allergic-Type Airway Reactions

Inflammatory allergic and nonallergic respiratory disorders are spreading worldwide and often coexist. The root cause is not clear. This review demonstrates that, from a biochemical point of view, it is ascribable to protons (H+) released into cells by exogenous and endogenous acids. The hypothesis of acids as the common cause stems from two considerations: (a) it has long been known that exogenous acids present in air pollutants can induce the irritation of epithelial surfaces, particularly the airways, inflammation, and bronchospasm; (b) according to recent articles, endogenous acids, generated in cells by phospholipases, play a key role in the biochemical mechanisms of initiation and progression of allergic-type reactions. Therefore, the intracellular acidification and consequent Ca2+ increase, induced by protons generated by either acid pollutants or endogenous phospholipases, may constitute the basic mechanism of the multimorbidity of these disorders, and environmental acidity may contribute to their spread.

Cross-reactivity between the Betulaceae family and fallout in the real atmospheric aeroallergen load

Betulaceae family is a dominant tree pollen type in the atmosphere at Northwest Spain, being a major cause of allergenic rhinitis or asthma symptoms. Alnus pollen cause symptoms in the 9-20% of the total hay fever sufferers mean while the 41.89% of patients present a positive skin-prick-test for Betula allergens. Aln g1 and Bet v1 aeroallergens belong to PR-10 protein family and are associated to cross-reactivity processes. Airborne pollen and aeroallergens from Alnus and Betula were sampled during their Main Pollen Season from 2016 to 2019. Pollen sampling was conducted by means of a Hirst volumetric trap and aeroallergens were sampled using a Multi Vial Cyclone Sampler. Alnus flowering took place from January to February, with an average duration of 44 days. Betula bloom occurred from April to May with an average pollen season of 33 days. The major innovation of our study was the first detection of Aln g1 allergens in the atmosphere by using Bet v1 antibodies. This fact verified the cross-reactivity between the main allergens of Betula and Alnus pollen. Along the study period, an average of 18 days/year and 14 days/year with high potential risk of allergy due to Alnus pollen and allergen respectively, was registered. For Betula an average of 16 days/year with high potential risk of allergy due to pollen and 22 days for allergen was registered. The main consequence of the successive bloom of both trees would be the so-called "priming effect". Urban population sensitized to Betula pollen could suffer allergic symptoms during winter (as a consequence of Alnus), and in spring with the manifestation of higher symptoms under low birch pollen grain levels in the atmosphere. The traditional information to prevent allergies, such as the airborne pollen concentrations, should be combined with the data of aeroallergen to identify the real allergenic load in the atmosphere.

The disease burden of childhood asthma in China: a systematic review and meta-analysis

Background

In China, childhood asthma prevalence showed a remarkable increase in the past decades. An updated epidemiological assessment of childhood asthma in China with a focus on prevalence and time trends is required.

Methods

We systematically searched three main Chinese databases and one English database to identify epidemiological studies of the prevalence of childhood asthma in China. Asthma cases were defined according to one of the five sets of Chinese diagnostic criteria which were established by the Children Respiratory Disease Group. We estimated age- and sex-specific prevalence of asthma using a multilevel mixed-effects logistic regression. We presented the time trends of asthma prevalence between 1990 and 2020 by age, sex and setting (urban vs rural), and also estimated the number of children affected by asthma in 2010.

Results

In 1990, the prevalence of asthma ranged from 0.13% (95% confidence interval (CI) = 0.10-0.20) in rural girls aged 14 years to 1.34% (95% CI = 1.11-1.67) in urban boys aged five years. In 2010, the overall prevalence of asthma in Chinese children aged 0-14 years was 2.12% (95% CI = 1.83-2.51), corresponding to 5.16 million children living with asthma. Children aged 5-9 years were with the highest prevalence estimate of 2.65% (95% CI = 2.31-3.12) and those aged 10-14 years were with the lowest (1.48%, 95% CI = 1.26-1.78). In 2020, it is expected that this disparity will continue, with the prevalence of asthma being at the lowest level among rural girls aged 14 years (1.11%, 95% CI = 0.82-1.54) and at the highest level among urban boys aged four years (10.27%, 95% CI = 8.61-12.18). Over the 30 years (1990-2020), the prevalence of asthma in children aged 0-14 years has increased in both sexes and settings, which was consistently the lowest in rural girls and the highest in urban boys.

Conclusions

This study shows that childhood asthma has been increasingly prevalent in China. Asthma is more frequent in boys and in rural areas. The detailed and systematic estimates of asthma prevalence in this study constitute the best currently available basis for policymaking, planning, and allocation of health and welfare resources related to the burden of childhood asthma in China.

The protective effect of rural life on mite sensitization disappears among urban migrants in the South of Vietnam

Background

Rapid urbanization combined with rural migration to urban areas in southern Vietnam could be risk factors for allergen sensitization, contributing to chronic respiratory diseases (CRD). We aimed to evaluate the prevalence of mite sensitization and its relation to house dust characteristics among rural and urban native and migrating populations with CRD.

Methods

Rural (n = 19) and urban (n = 46) dwellings were defined on the basis of a home typology. Controls were western Belgian houses (n = 14). Besides the house characteristics, both endotoxin and mite allergens were measured in the settled dusts. The sensitization to mite allergens was defined by positive skin prick test (SPT) and concentration of specific IgE (sIgE)≥ 0.7 U/mL. The prevalence of mite sensitization was evaluated among 610 patients with CRD and compared according to both their home types and places of birth and residences.

Results

The concentration of endotoxin (but not mite allergen) was higher in rural compared to urban dusts (440 (95%CI: 314–566) versus 170 (95%CI: 115–226) EU/mg; p < 0.0001). The prevalence of positive sIgE to Der p1 and Der p2 was significantly lower in rural (9% and 5%) compared to urban (15% and 9%) population, consistent with the positive SPT to mite (14% and 21%, respectively). Among the urban migrants, the risk of mite sensitization (SPT) was higher compared to the rural natives (OR: 1.79 (1.02–3.15), p < 0.05) and not different to the urban ones (OR: 1.35 (0.82–2.23) p NS).

Conclusion

In Vietnam, associated with higher endotoxin (but not allergen) dust concentrations, the risk of mite sensitization was lower in rural compared to the native urban population, but this protective effect could disappear among rural to urban migrants.

Urbanisation and asthma in low-income and middle-income countries: a systematic review of the urban-rural differences in asthma prevalence

BACKGROUND

Urbanisation has been associated with temporal and geographical differences in asthma prevalence in low-income and middle-income countries (LMICs). However, little is known of the mechanisms by which urbanisation and asthma are associated, perhaps explained by the methodological approaches used to assess the urbanisation-asthma relationship.

OBJECTIVE

This review evaluated how epidemiological studies have assessed the relationship between asthma and urbanisation in LMICs, and explored urban/rural differences in asthma prevalence.

METHODS

Asthma studies comparing urban/rural areas, comparing cities and examining intraurban variation were assessed for eligibility. Included publications were evaluated for methodological quality and pooled OR were calculated to indicate the risk of asthma in urban over rural areas.

RESULTS

Seventy articles were included in our analysis. Sixty-three compared asthma prevalence between urban and rural areas, five compared asthma prevalence between cities and two examined intraurban variation in asthma prevalence. Urban residence was associated with a higher prevalence of asthma, regardless of asthma definition: current-wheeze OR:1.46 (95% CI:1.22 to 1.74), doctor diagnosis OR:1.89 (95% CI:1.47 to 2.41), wheeze-ever OR:1.44 (95% CI:1.15 to 1.81), self-reported asthma OR:1.77 (95% CI:1.33 to 2.35), asthma questionnaire OR:1.52 (95% CI:1.06 to 2.16) and exercise challenge OR:1.96 (95% CI:1.32 to 2.91).

CONCLUSIONS

Most evidence for the relationship between urbanisation and asthma in LMICs comes from studies comparing urban and rural areas. These studies tend to show a greater prevalence of asthma in urban compared to rural populations. However, these studies have been unable to identify which specific characteristics of the urbanisation process may be responsible. An approach to understand how different dimensions of urbanisation, using contextual household and individual indicators, is needed for a better understanding of how urbanisation affects asthma.

PROSPERO REGISTRATION NUMBER

CRD42017064470.

21st century research in urban WASH and health in sub-Saharan Africa: methods and outcomes in transition

Tackling global inequalities in access to Water, Sanitation and Hygiene (WASH) remains an urgent issue - 58% of annual diarrhoeal deaths are caused by inadequate WASH provision. A global context of increasing urbanisation, changing demographics and health transitions demands an understanding and impact of WASH on a broad set of health outcomes. We examine the literature, in terms of health outcomes, considering WASH access and interventions in urban sub-Saharan Africa from 2000 to 2017. Our review of studies which evaluate the effectiveness of specific WASH interventions, reveals an emphasis of WASH research on acute communicable diseases, particularly diarrhoeal diseases. In contrast, chronic communicable and non-communicable health outcomes were notable gaps in the literature as well as a lack of focus on cross-cutting issues, such as ageing, well-being and gender equality. We recommend a broader focus of WASH research and interventions in urban Africa to better reflect the demographic and health transitions happening. Abbreviations: CBA: Controlled Before and After; GSD: Government Service Delivery; IWDSSD: International Drinking-Water, Supply and Sanitation Decade (IDWSSD); KAP: Knowledge, Attitudes and Practices; IBD: Irritable Bowel Diseases; MDG: Millennium Development Goals; NTD: Neglected Tropical Diseases; PSSD: Private Sector Service Delivery; SDG: Sustainable Development Goals; SSA: Sub Saharan Africa; SODIS: Solar Disinfection System; STH: Soil Transmitted Helminths; RCT: Randomised Control Trial; WASH: Water Sanitation and Hygiene; WHO: World Health Organization.

Applying Deep Neural Networks and Ensemble Machine Learning Methods to Forecast Airborne Ambrosia Pollen

Allergies to airborne pollen are a significant issue affecting millions of Americans. Consequently, accurately predicting the daily concentration of airborne pollen is of significant public benefit in providing timely alerts. This study presents a method for the robust estimation of the concentration of airborne Ambrosia pollen using a suite of machine learning approaches including deep learning and ensemble learners. Each of these machine learning approaches utilize data from the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric weather and land surface reanalysis. The machine learning approaches used for developing a suite of empirical models are deep neural networks, extreme gradient boosting, random forests and Bayesian ridge regression methods for developing our predictive model. The training data included twenty-four years of daily pollen concentration measurements together with ECMWF weather and land surface reanalysis data from 1987 to 2011 is used to develop the machine learning predictive models. The last six years of the dataset from 2012 to 2017 is used to independently test the performance of the machine learning models. The correlation coefficients between the estimated and actual pollen abundance for the independent validation datasets for the deep neural networks, random forest, extreme gradient boosting and Bayesian ridge were 0.82, 0.81, 0.81 and 0.75 respectively, showing that machine learning can be used to effectively forecast the concentrations of airborne pollen.

The Impact of Intensive Versus Standard Anthelminthic Treatment on Allergy-related Outcomes, Helminth Infection Intensity, and Helminth-related Morbidity in Lake Victoria Fishing Communities, Uganda: Results From the LaVIISWA Cluster-randomized Trial

BACKGROUND

The prevalence of allergy-related diseases is increasing in low-income countries. Parasitic helminths, common in these settings, may be protective. We hypothesized that intensive, community-wide, anthelminthic mass drug administration (MDA) would increase allergy-related diseases, while reducing helminth-related morbidity.

METHODS

In an open, cluster-randomized trial (ISRCTN47196031), we randomized 26 high-schistosomiasis-transmission fishing villages in Lake Victoria, Uganda, in a 1:1 ratio to receive community-wide intensive (quarterly single-dose praziquantel plus albendazole daily for 3 days) or standard (annual praziquantel plus 6 monthly single-dose albendazole) MDA. Primary outcomes were recent wheezing, skin prick test positivity (SPT), and allergen-specific immunoglobulin E (asIgE) after 3 years of intervention. Secondary outcomes included helminths, haemoglobin, and hepatosplenomegaly.

RESULTS

The outcome survey comprised 3350 individuals. Intensive MDA had no effect on wheezing (risk ratio [RR] 1.11, 95% confidence interval [CI] 0.64-1.93), SPT (RR 1.10, 95% CI 0.85-1.42), or asIgE (RR 0.96, 95% CI 0.82-1.12). Intensive MDA reduced Schistosoma mansoni infection intensity: the prevalence from Kato Katz examinations of single stool samples from each patient was 23% versus 39% (RR 0.70, 95% CI 0.55-0.88), but the urine circulating cathodic antigen test remained positive in 85% participants in both trial arms. Hookworm prevalence was 8% versus 11% (RR 0.55, 95% CI 0.31-1.00). There were no differences in anemia or hepatospenomegaly between trial arms.

CONCLUSIONS

Despite reductions in S. mansoni intensity and hookworm prevalence, intensive MDA had no effect on atopy, allergy-related diseases, or helminth-related pathology. This could be due to sustained low-intensity infections; thus, a causal link between helminths and allergy outcomes cannot be discounted. Intensive community-based MDA has a limited impact in high-schistosomiasis-transmission fishing communities, in the absence of other interventions.

CLINICAL TRIALS REGISTRATION

ISRCTN47196031.

Exposure to pollen allergens in allergic rhinitis expressed by diurnal variation of airborne tree pollen in urban and rural area

Exposure to airborne pollen allergens results in allergic symptoms in subjects who are sensitized. The paper presents diurnal variation in the counts of airborne allergenic pollen of selected trees (Betula L., Alnus Mill., Corylus L., Fagus L. and Ulmus L.) in two localities differing in the degree of urbanization: the city of Szczecin (urban) and the village of Gudowo, West Pomerania in northwest Poland (rural) in the years 2012–2014. The measurements were made by the volumetric method using a Burkardtype sampler operating in a continuous mode. The greatest similarities in the beginning of the main pollen season between the two sites studied were observed for birch and elm trees, while in the length of the main pollen season, for birch and alder trees. Pollen counts of alder and hazel reached higher levels in the rural area, while the levels of ash tree pollen counts were higher in the urban area. The level of birch tree pollen counts was similar in the two sites studied. For the majority of taxons observed in the urban and rural areas the dynamics of hourly changes in tree pollen counts were similar. The pollination peak was noted in the daytime, usually in the afternoon. For ash and elm trees increased pollen counts were observed at nighttime, while the birch tree pollen counts were at a high level for most of the 24 h cycle. The knowledge of seasonal and diurnal variations in tree pollen counts is crucial for prevention in patients with allergic rhinitis, sensitized to tree pollen allergens.

Old Friends, immunoregulation, and stress resilience

There is a considerable body of evidence indicating that chronic adverse experience, especially chronic psychosocial stress/trauma, represents a major risk factor for the development of many somatic and affective disorders, including inflammatory bowel disease (IBD) and posttraumatic stress disorder (PTSD). However, the mechanisms underlying the development of chronic stress-associated disorders are still in large part unknown, and current treatment and prevention strategies lack efficacy and reliability. A greater understanding of mechanisms involved in the development and persistence of chronic stress-induced disorders may lead to novel approaches to prevention and treatment of these disorders. In this review, we provide evidence indicating that increases in immune (re-)activity and inflammation, potentially promoted by a reduced exposure to immunoregulatory microorganisms ("Old Friends") in today's modern society, may be causal factors in mediating the vulnerability to development and persistence of stress-related pathologies. Moreover, we discuss strategies to increase immunoregulatory processes and attenuate inflammation, as for instance contact with immunoregulatory Old Friends, which appears to be a promising strategy to promote stress resilience and to prevent/treat chronic stress-related disorders.

Do helminth infections underpin urban-rural differences in risk factors for allergy-related outcomes?

Background

It is proposed that helminth exposure protects against allergy‐related disease, by mechanisms that include disconnecting risk factors (such as atopy) from effector responses.

Objective

We aimed to assess how helminth exposure influences rural‐urban differences in risk factors for allergy‐related outcomes in tropical low‐ and middle‐income countries.

Methods

In cross‐sectional surveys in Ugandan rural Schistosoma mansoni (Sm)‐endemic islands, and in nearby mainland urban communities with lower helminth exposure, we assessed risk factors for atopy (allergen‐specific skin prick test [SPT] reactivity and IgE [asIgE] sensitization) and clinical allergy‐related outcomes (wheeze, urticaria, rhinitis and visible flexural dermatitis), and effect modification by Sm exposure.

Results

Dermatitis and SPT reactivity were more prevalent among urban participants, urticaria and asIgE sensitization among rural participants. Pairwise associations between clinical outcomes, and between atopy and clinical outcomes, were stronger in the urban survey. In the rural survey, SPT positivity was inversely associated with bathing in lakewater, Schistosoma‐specific IgG4 and Sm infection. In the urban survey, SPT positivity was positively associated with age, non‐Ugandan maternal tribe, being born in a city/town, BCG scar and light Sm infection. Setting (rural vs urban) was an effect modifier for risk factors including Sm‐ and Schistosoma‐specific IgG4. In both surveys, the dominant risk factors for asIgE sensitization were Schistosoma‐specific antibody levels and helminth infections. Handwashing and recent malaria treatment reduced odds of asIgE sensitization among rural but not urban participants. Risk factors for clinical outcomes also differed by setting. Despite suggestive trends, we did not find sufficient evidence to conclude that helminth (Sm) exposure explained rural‐urban differences in risk factors.

Conclusions and clinical relevance

Risk factors for allergy‐related outcomes differ between rural and urban communities in Uganda but helminth exposure is unlikely to be the sole mechanism of the observed effect modification between the two settings. Other environmental exposures may contribute significantly.